Information for Clinicians about Sperm Aneuploidy

Chromosomal abnormalities may be somatic cell in origin, in which case they can be detected by a simple blood karyotype analysis. However, most sperm chromosome anomalies arise as a result of errors during meiosis, which cannot be detected by a blood karyotype analysis. These anomalies can only be detected by looking at the sperm chromosomes directly.

Sperm Aneuploidy and Semen Parameters
Approximately 2 to 13% of all sperm are genetically abnormal in normally fertile men. There is evidence that this percentage may be increased in men who are subfertile. Studies have shown a relationship between poor sperm parameters and increased sperm aneuploidy. There  is no direct correlation between sperm morphology and aneuploidy, and indeed, sperm aneuploidy can also be found in sperm with normal morphology. However, particular types of morphological defects may be linked to a significant increase in sperm aneuploidy rate, including globozoospermia, amorphous heads, severe tail defects and macrocephalic or multiple head defects.

High Rates of Sperm Aneuploidy and Pregnancy

Studies have shown that sperm with a high rate of aneuploidy have a negative impact on pregnancy rate and are associated with recurrent pregnancy loss.

Measuring sperm aneuploidy
This test uses fluorescent in situ hybridisation (FISH) to label individual chromosomes with specific probes. Hundreds of sperm are assessed from one  ejaculate. There are limitations to the test as only 5 probes are currently used routinely for analysis (three of the 22 autosomes: chromosomes 13, 18 and 21, and the sex chromosomes, X and Y), although others are available upon specific request. The results are reported showing incidence of disomy or nullisomy for each of the autosomes and for both sex chromosomes. A sex chromosome ratio is also reported.  It usually takes about 14 days to receive the results.

Indications for male patients who may benefit from the test
•    unexplained infertility
•    multiple failed IVF/ICSI treatment
•    recurrent miscarriage in partner

•    raised FSH

•    oligoasthenoteratozoospermia

•    severe teratozoospermia

Causes of sperm aneuploidy
•    cigarette smoking
•    caffeine
•    alcohol
•    certain drugs
•    chemotherapy and radiotherapy treatment within the last 2 years

•    exposure to environmental and occupational pollutants
•    exposure to ionising radiation
•    advanced age

Treatment
A change in lifestyle may help to reduce these levels in sperm. However, some abnormalities may be irreversible. A recent study indicates that high folate intake may maintain lower aneuploidy rates. There are some studies to show that the use of hyaluronic acid for the selection of genetically healthy sperm for ICSI may be beneficial. 

Additional information downloads:

Sperm DNA Fragmentation and Aneuploidy/Sample Information Sheet and Request Form (Word doc, 56Kb)

REFERENCES 

Tempest HG and Martin RH (2009) Cytogenetic risks in chromosomally normal infertile men. Curr Opin Obstet Gynecol. 21(3):223-7

Young SS, Eskenazi B, Marchetti FM, Block G and Wyrobek AJ (2008) The association of folate, zinc and antioxidant intake with sperm aneuploidy in healthy non-smoking men. Huamn Reprod.23(5):1014-22.

Faure AK, Aknin-Seifer I, Frerot G, Pelletier R, De Robertis C, Levy R, Jimenez C, Lejeune H, Terrier N, Bergues U, Hennebicq S and Rousseaux S (2007) Predictive factors for an increased risk of sperm aneuploidies in oligoasthenoteratozoospermic males. Int J Androl 30 (3): 153 – 162

Carrell DT (2007) The clinical implementation of sperm chromosome aneuploidy testing: pitfalls and promises. J Androl. 29(2):124-33.
 
Huszar G, Jakab A, Sakkas D, Ozenci CC, Cayli S, Delpiano E, Ozkavukcu S (2007) Fertility testing and ICSI sperm selection by hyaluronic acid binding: clinical and genetic aspects. Reprod Biomed Online 14(5):650-663

Sun F, Ko E and Martin RH (2006) Is there a relationship between sperm chromosome abnormalities and sperm morphology? Reprod Biol Endocrinol 4:1 Review

Collodel G and Moretti E (2006) Sperm morphology and aneuploidies: defects of supposed genetic origin. 38(6):208-15.
 
Pang MG, Kim YJ, Lee SH and Kim CK (2005) The high incidence of meiotic errors increases with decreased sperm count in severe male factor infertilities. Hum Reprod. 20(6):1688-94.

Gianaroli L, Magli MC, Cavallini G,  Crippa A, Nadalini M, Bernardini L, Fabris GFM, Voliani S and Ferraretti AP (2005) Frequency of aneuploidy in sperm from patients with extremely severe male factor infertility. Hum Reprod. 20(8):2140-2152

Robbins WA, Elashoff DA, Xun L, Jia J, Li N, Wu G and Wei F (2005) Effect of lifestyle exposures on sperm aneuploidy. Cytogenet Genome Res.;111(3-4):371-7. Review.

Harkonen K (2005) Pesticides and the induction of aneuploidy in human sperm. Ctyogenet. Genome Res. 111 (3-4): 378-83

Celik-Ozenci C, Jakab A, Kovacs T, Catalanotti J, Demir R, Bray-Ward P, Ward D and Huszar G (2004) Sperm selection for ICSI: shape properties do not predict the absence or presence of numerical chromosomal aberrations. Human Reproduction  19(9):2052-2059

Burrello N, Vicari E, Shin P, Agarwal A, De Palma A, Grazioso C, D'Agata R, Calogero AE. (2003) Lower sperm aneuploidy frequency is associated with high pregnancy rates in ICSI programmes. Hum Reprod. Jul; 18(7): 1371-6.

Carrell DT, Wilcox AL, Lowy L, Peterson CM, Jones KP, Erickson L, Campbell B, Branch DW, Hatasaka HH.. (2003) Elevated sperm chromosome aneuploidy and apoptosis in patients with unexplained recurrent pregnancy loss. Obstet Gynecol Jun;101(6):1229-35

Robbins WA (2003) FISH (fluorescence in situ hybridization) to detect effects of smoking, caffeine and alcohol on human sperm chromosomes. Adv. Exp. Med. Biol. 518:59-72